Hot Rods CHEVY help needed

while laying around recouping from TKR on my right knee, i'm trying to dig up info to help a buddy with C2 coupe whose 327 is well worn out,who wants to build up a 350 to replace it,start on some very mild retroroding, IE disc brakes from stock non power drums,

he has instock a 1987 638 casting truck long block, fresh rebuilt 462 double hump heads, a 327/350 hp NOS cam and kit, the block dose have all the needed goodies and machining to switch from flat to roller, 4 bolt mains.

will the 462's bolt down and work on the gen 2 block? help keep the car look and sound stock nasty yet have a stronger motor

 

Yes, heads will bolt down the the ‘87 block.

 

thanks, knowing that it seems i could build him nice sounding stock 350 use most of his instock parts s

 

Well crank is different for the 1pc RMS block.

Edit: I see you have a long block to work with never mind on the crank

 

will need a different flywheel, though

 

flywheel just happens to be bolted to the crank , that i was aware of being different, and bigger 11 inch ver 10.5 clutch i'm thinking a new set of flattop pistons, maybe .020 over bore if needed the 462 heads the instock 327 /350 intake and carb , nice strong low end yet look almost stock

 

So the block is all complete minus the intake and accessories? Is it a factory roller block? I know you said it was machined for it. Those GM factory roller lifters last forever.

 

I’m not sure what bell housing the c2 has but it may not fit the 11” truck flywheel. The smaller flywheel is available that is externally balanced. I used a cheap aftermarket one to put on an already running engine and the balance wasn’t even close. Better to work that out while it’s all apart to avoid problems when it’s finished. Also those heads with 4 relief pistons will be around 10:1 compression.

 

yes it's fully machined for a roller cam kit only since it was pulled under warranty for piston knock noises from a Hd truck, so it has flat tappets ,
yes a full long block less the intake as the techs had to swap those over

 

that i'm aware of, stock 327 /300 hp used flat tops with double humps was 1o.0 compression
bell i'm not worried have both sizes in stock ,will need to use gear reduction 168 tooth starter at the machine shop he can check the balance and do whats needed

 

Also did you see if it will except a mechanical fuel pump? Assuming that’s what you want to run. I’v seen were the boss is cast on the block but they didn’t machine the hole for the pump pushrod.

 

BE CAREFUL IT MAY NOT ACCEPT ROLLER EVEN IF IT LOOKS LIKE IT SHOULD !!!!

Whoops, I just reread your post and it states the block WILL accept roller stuff but it seems you AREN'T intending on running roller stuff. The text written below was written before this paragraph because I thought you wanted to swap to roller stuff. Maybe the info below is something to keep in mind though if the thought of a roller swap crosses the table at some point in the future.

I had a 1987 block as well but it was a 305 from a 1987 Monte SS that came with flat tappets. According to a magazine article I read "If the lifter valley has the bosses for the dog bone spider, it will accept a factory roller cam, even if the bosses aren't drilled and threaded". After reading and verifying that I did indeed have the lifter valley bosses that, in my case were not drilled and threaded, I went ahead and purchased everything needed to complete the change from flat to roller. It did NOT work in my case. After much head scratching (I have an old thread on this site specifically about this problem) it was determined that the factory had performed a second machining operation to the lifter bores and this machining operation prevented the use of roller lifters. The lifter bores where "stepped", not uniform from top to bottom. The lifters fit as they should have but due to the step, part of the lifter ended up being exposed (being that the roller lifter is taller than a flat) and the end result was oil spraying everywhere (inside the lifter valley, under the intake), being released from the lifter when it should have been forced up the pushrod. The engine ran on my test stand but luckily I found the problem before I installed the engine in a car. I ended up locating a 1995 flat tappet (from a truck) that did not have the stepped lifter bores and swapped in my roller stuff. Being that the block you are talking about is also from 1987, I'd make sure the lifter bores aren't stepped before anyone moves forward with the roller conversion. Keep in mind, this block had the appearance of being perfectly capable of accepting the swap to a factory roller cam ... the cam thrust surface was flat and accepted the retainer, the lifter bores were the correct height and flat on top, to accept the roller lifters and the dog bones, and the lifter valley had the bosses for spider retention ... EVERYTHING appeared roller correct and was except for the stepped lifter bore.

As an aside, I installed early heads and an early carb intake on the 1995 block (no problems at all) and used a factory, old style (carb type) HEI with no issues although I did change the HEI gear to a 'melonized' factory gear to work with the roller cam. Ran it for years.

Here is my thread from when I was searching for an answer as to why my supposedly roller compatible block wouldn't work with roller components: https://www.jalopyjournal.com/forum/threads/sbc-factory-roller-lifter-problems.478632/page-2

Here is a pic of the stepped lifter bores. I have no idea why they did this but they did and being that your block is also a 1987, you need to check your lifter bores. If they don't have the step you should be good to go.

 

Never hear about that. I have a marine block that is 1989ish. The bores were stepped but the bosses in the valley were not milled to proper height or tapped to bolt the lifter tray. I milled and tapped them and it’s running great with a factory GM Hot cam. Hope you can find the thread.

 

yes machined fully for a mechanical fuel pump and has the dog bone bosses machined and tapped , plus flat machined lifter bores , thrust plate drilled and tapped just like every day roller cam

 

Are you planning on purchasing the roller cam and pieces, or going to use the NOS (327/350) 151 cam with hydraulic flat tappets?

 

The OP here has heads....but...Trick Flow and a few other manufacturers make new aluminum double hump heads with the vintage look. The feature the newer fast burn chambers and better flow than stock 462 type heads. While not inexpensive, they are better than putting money into old heads..And less weight...

 

Being that you have the block ready for roller cam, I would lean that way. Why the risk and worry about the flat tappet break-in and reliability? The roller cam can provide more performance than the old 327/350 cam, while having the same basic duration specs.

 

I did a bunch of editing to my post and the link to my earlier thread on the roller topic is included. The stepped bore worked fine with flat tappets but would not work with the roller due to too much of the roller lifter being exposed (although the engine ran fine on the stand). It was a complete fluke that I found it. If you are running a roller in a stepped-lifter block, you may have a problem you aren't aware of, regardless of how well the engine is running now.



Is this "factory hot cam" roller or flat?

 

It’s a roller cam now. It was originally a flat.
Edit. Just looked at your pic. I’m ok I thought the step you were talking about was for the lifter plates to set in.
Your info is very helpful I was never aware of that.

 

I would definitely take advantage of the option to swap to roller if this was my project.

 

Sounds like what I did with my 1990 GMC SBC 350 motor. I used 1970-71 LT1 heads with the later 1990 block. I also had an engine that was machined for a mechanical fuel pump, so bought the rod and plate, and converted it to the mechanical pump. I went with a Howards roller cam, and lifters with the earlier heads. Never having owned a late block with 1 piece main seal, I discovered I had to buy a lot of parts my short block didn't have with it when I bought it. Like a different pan, flywheel, dipstick, rear main seal housing, etc. But once I finally got it all together it's a great combo of old heads and intake, with newer roller bottom end and 1 piece main seal.

 

Mark
A bit off topic but the 67 CacaCamaro 350 block also had the rear fresh air tube port.

 

The L79 is a flat tappet hydraulic cam. If that is what he is going to use it, I would probably use flat tappets.

I could use a well worn 327, maybe we could swap technical help for the old motor. LOL

The heads are interchangeable until GM went to the LS. Get a good set of head bolts or studs from a company like ARP, tell the vendor what heads you are running. I would look and make sure that the slugs stop somewhere near the deck before I wasted anytime with the heads. If you are going to run those heads you want to keep your quench tight.

 

thanks for all the advise guys, this isn't my first rodeo with chevys, just my first sticking old heads on a newer 1 piece seal block. for stinks and giggles i'm old enough to have gone to gm school for the old rochester fuelie units, when i worked for Malcolm Konner chevy along the side of eddie night . working on vettes

the block is not stepped in the lifter bores. the lifters stay all the way up in a straight bore , i am planning on using the nos 327/350 cam, 327/350 intake ,camel hump heads that i did myself many years back that had hardened seats installed , ss valves, lightly ported gasket matched . the stock dished pistons are going byby, for sure flat tops maybe pop tops if i turn up a set instock and in the needed size the machine shop goes to, it will be both internal and external balanced why buy when one has nos

 

Well, now were talk'n!
This is my L79/327/325 hp engine for my Nova (same as the 350 hp engine).


I got lucky many years ago when I found all my GM issue engine pieces, a Chevy parts counterman had been hoarding this stuff for a build, then changed plans.
Forged small journal crank, rods, #151" camshaft, lifters, balancer, flywheel, "291" heads with GM valves, retainers, keepers, etc, even a set of the "O" stamped rocker arms and locknuts.
The Winters intake manifold and Delco distributor are new also as are many other odds and ends.
All are NOS except the block, TRW 11 to 1 pistons and timing set.
By the way, I have lived behind a GM training center for 50 years (now closed), always wondered about the magic that went on in that building.

 

lots of magic went on in there, sadly many of the old techs are taking what they learned with them when they pass, how many guys today know how to tune and repair a Rochester injection unit?
motor wise i just want a good strong motor that fails to mark it's spot when parked

 

I have done many L79 clones. Here is a picture of one I did in my Chevy II as well as my Malibu. FUN motors.
Have another on the engine stand waiting to be put together when I find my next project. Keep us posted on
how it turns out......very cool!!